Improved apparatus for tempering chisels



y UNITED STATES PATENT* OFFICE.

wM. M. EVEEITT, or MALDEN, `NEW YORK.

Specification forming part of Letters Patent No. 56,916, dated August 7,1866.

To all whoml t may concern:

Be it known that I, WILLIAM M. EVERITT, of Malden, Ulster county, Stateot' New York, have invented certain new and useful Improvements inTempering or Hardening the Edges or Points ot' Ohisels for Planing orCutting Stone; and I do hereby declare that the following is a. fulldescription ofthe same.

The object of' my inventionis to obviate the great difficulty heretoforeexperienced by' stone-cutters in dressing or cutting stone by machineryin` preserving the cutting edges or points of the chisels from breakingimmediately on being subjected to any unusually h ard labor. The commonpractice of preparing the chisel for such work has been to harden ortemper the chisbl as far as red-hot. Experience, however, has shown thatwhen they have been tempered in this manner they will not endure anylabor; but, on the contrary, when coming in contact with any hardsubstance or seam 1n the stone, the end'ot' the chisel is immediatelybroken` ata point varying from half an inch to one inch from thecutting-edge. The consequence ot this is not only the greater labor ofdrawing down the point f the chisel again, but also the loss ot' themetal thus broken oft', as it is found practically impos-` sible to weldthe short end of the chisel on the stock again to make anything like adurat ble chisel.

My invention, therefore, is to overcome these objections; and the natureof my invention consists in hardening or tempering the point or edge ofthe `chisel for about one`-eighth to half an inch deep only, whileleaving the stock or body of the chisel untempered, or in its naturalstate, thereby retaining all the toughness of the ber of the metal, toprevent its being broken when coming in contact with hard obstructionsin the stone, which operation is effected by means of a rack adjusted ina tub of water that suspends or holds the chisel in a vertical position,or nearly so,` with the point of the chisel immersed in the water to adepth not exceeding one-eighth of an inch, or onehalf an inch at theoutside. y

But to describe my invention more particularly I will refer to theaccompanying drawing, forming a part of this speciiication, the sameletters of reference, wherever they occur, referring to like parts.

Figure l is a perspective view of the teInpering-bath and raclgforsupporting the'chisel with the chisel arranged thereon.

Letter A is an ordinary tub or bath ofl water. Across the inside of it,near its upper edge, is secured a table, B, which is just submerged inthe water-that is, the water is never to be more than about one-eighthto half an inch deep on it. The object-'ot' this is t0 prevent the pointofthe chisel C from being chilled or hardened to a greater depth thanthe depth of the water covering the table.

To keep the chisel in a vertical position, or nearly so, a rack, D, issecured to the side of the tub and sufficiently elevated to allow thestock of the chisel to rest against it until the point is hardened.

By this arrangement it will be perceived that the point of the chiselonly is tempered, and at the same time with the greatest uniformity oftemper and t depth to which the point is hardened, as well as with greatrapidity, as the temperingman has only to obtain the proper heat ot thechisel in the forge and place on the rack in the bath to obtain thetemper of` the chisel; wher-eas, if attempted to be tempered at thepoint not eX- ceeding in depth an eighth of an inch or more "than halfan inch by dipping by band in the water, it would not only beexceedingly dii- -cult to limit the immersion of the chisel to theVproper depth, but alsowould take up a great deal ot' time where manychisels are required t to be sharpened.

These chisels are more especially intended for use in stone-dressingmachinery as applied to planing the blue tlagstone, but may be used Vinany machinery for planing sandstone or marble with equally good result,as all chisels used in machinery for such purposes are subject toconstant breakage from the same causes that operate to break them inplaning the blue flag-stonepthat` is, having the stock of the chiselhardened throughout its entire length,`

wM. M. EvEErT'r.

Witnesses:

` WM. S. VAN HoEsEN,

G. N. HUMMEL.

